Needle roller guide provides a few microns preload to roller between post and bush by arranging roller on six surface, whose contact area is several times larger than ball. Therefore it has maintained not only rigidity and straightness of die set but also smooth up and down stroke and stable accuracy for a long time, and improved durability against high speed intermittent operation and vibration.

Roller arrangement doubly in stable three-point support achieves rigidity close to plain guide, and shows rigidity, accuracy and high-speed performance unobtainable with using ball.

Contact area of roller is about 10 times larger than that of ball, and the use of roller increases rigidity between guide post and guide bush. In the case of ball, preload is raised to 0.01-0.02mm aiming to increase rigidity, but shock is large and vibration occurs when ball is inserted.

The preload of Needle is kept a few microns to move smoothly and reduce insertion shock.